When using DRV11873 to start the brushless motor, there are three situations as follows (what we need is to rotate the motor counterclockwise) :
(1) Extreme case: has been clockwise rotation;
② Common situation: interval clockwise rotation (clockwise -- stop -- clockwise -- stop...);
The instantaneous clockwise rotation speed shall not exceed 150rpm.
③ Occasional situation: stop counterclockwise rotation (turn a stop, the speed is very low, visible to the naked eye)
Preliminary analysis of the starting process: once the PWM signal is obtained, the device will start the motor at 100% duty cycle until sufficient BEMF is generated (4 zero crossings are required);Once this happens, the device will enter closed-loop control and enter command speed based on PWM input.
Question: 1. Why does the motor chip rotate clockwise after obtaining PWM signal?What could possibly be causing this?How do we debug by hardware or software?
2. Once the PWM signal is obtained, is it possible to start the motor with a low duty cycle instead of 100% duty cycle? What parameters need to be adjusted?
Please help to analyze the above, thank you
